Field of the Invention
The present invention relates to a thin layer chromatography plate (hereinafter also referred to as “TLC plate”) containing two types of layers having different optical responses to ultraviolet rays.
Description of the Related Art
Thin layer chromatography (hereinafter also referred to as “TLC”) is a known method for separating and detecting specific substances in mixtures. Separation of substances by TLC is detected for example on the basis of differential optical responses between a separating medium layer and a substance to be detected, by subjecting developed spots of samples to irradiation of ultraviolet rays or colour development treatment using a chromogenic reagent.
Meanwhile known separating media for optical isomers include separating media containing polysaccharide derivatives such as phenyl esters of polysaccharides. When such separating media containing aromatic rings are used for the separating medium layers of TLC plates, a substance may not be detected by the irradiation of ultraviolet rays or colour development treatment using a chromogenic reagent.
In order to address such a problem, a TLC plate is known which contains, on the same substrate in parallel, a first separating medium layer that has a separating property for a target substance but does not have an optical responsiveness and a second separating medium layer that does not have the separating property but has an optical responsiveness (see, for example, Japanese Patent No. 3140138). In this TLC plate, a target substance in a sample is developed from the first separating medium layer to the second separating medium layer, and the spots separated in the first separating medium layer migrate to the second separating medium layer and are detected therein depending on the optical responsiveness thereof.
In this TLC plate, an extracted component in the samples that is easily adsorbable by the first separating medium layer may not sufficiently reach the second separating medium layer. In addition, because the migration speed of the spots of the target substance in the sample is generally different between the respective separating medium layers, the relative positions of the spots in the first separating medium layer may not be accurately maintained in the second separating medium layer. Accordingly this TLC plate may not allow the accurate detection of the separation in the first separating medium layer, leaving room for improvement in this point.